The present invention relates to triazole derivatives having excellent activity against a wide range of fungi, to certain of said derivatives in crystalline form, to a pharmaceutical composition containing said derivatives, to a method of treating and preventing fungal infections using said derivatives and to an intermediate useful in the preparation of said derivatives.
Antifungal triazole derivatives having the following general formula are disclosed in Japanese Patent Application (Kokai) Hei 8-333350 and EP-A-0841327: 
wherein Ra represents a hydrogen atom or an alkyl group, Rb represents an alkyl group, Ar1 and Ar2 can each represent an optionally substituted phenyl group, q and r can each represent 1, and each of Rc, Rd, Re and Rf can represent a hydrogen atom. Similar compounds, in which the sulfur atom is replaced by a methylene group are disclosed in Japanese Patent Application (Kokai) Hei 11-80135 and WO-A-99/02524.
These prior art compounds show good antifungal activity. There is, however, a need for further compounds having improved antifungal activity, stability, pharmacokinetics and safety.
It is therefore an object of the present invention to provide a series of new compounds having antifungal activity.
Other objects and advantages of the present invention will become apparent as the description proceeds.
The compounds of the present invention are compounds of the following formula (I), and pharmaceutically acceptable salts and ester derivatives thereof: 
wherein Ar is a phenyl group which may optionally be substituted by from 1 to 3 substituents selected from the group consisting of halogen atoms and trifluoromethyl groups.
The present invention also provides the compound (2R,3R)-3-[[trans-2-[(1E,3E)-4-(4-cyano-2-fluorophenyl)-1,3-butadien-1-yl]-1,3-dioxan-5-yl ]thio]-2-(2,4-difluorophenyl)-1-(1H-1,2,4-triazol-1-yl)-2-butanol [formula (Ib) below] in crystalline form: 
The present invention also provides a pharmaceutical composition comprising an effective amount of a pharmacologically active compound together with a pharmaceutically acceptable carrier therefor, wherein said pharmacologically active compound is a compound of formula (I) or a pharmaceutically acceptable salt or ester derivative thereof.
The present invention also provides a method for the prophylaxis or treatment of fungal infections in a mammal, which may be a human, which comprises administering to said mammal an effective amount of a compound having antifungal activity, wherein said compound having antifungal activity is a compound of formula (I) or a pharmaceutically acceptable salt or ester derivative thereof.